Variable dilution filter

ABSTRACT

Smoking article (10) has a filter mouthpiece (14) with a first stage filter element (18) and second stage filter element (19). First stage filter element (18) is rigidly attached to tipping paper (22). Second stage filter element (19) is free to move longitudinally in mouthpiece (14) and may be made to move axially by tapping the cigarette, thus, covering some of the ventilation holes (16) and changing the smoke to air ratio and the flavor.

BACKGROUND OF THE INVENTION

This invention relates to smoking articles in general and moreparticularly to a ventilated cigarette with means to adjust the smoke toventilation air ratio.

DESCRIPTION OF THE PRIOR ART

The current trend in cigarette manufacturing has been to reduce theconcentration of certain components of smoke. For example, filters madeof fibrous materials such as cellulose acetate are used to lower theconcentration of particulate matter in the smoke generated in smoking.Ventilation into the filter has been used to further reduce theconcentration of particulate matter and also to lower the concentrationof gas phase components.

Filtration of the smoke and ventilation into the cigarette filter bothaffect the flavor of the cigarette. In particular, as ventilation isincreased and smoke to ventilation air ratio is reduced, the flavor ofthe cigarette is reduced. Since the ventilation ratio on most cigarettesis fixed at the factory, a smoker not satisfied with the flavor of aparticular cigarette would have no choice but to change brands, when allhe was dissatisfied with was the highly diluted flavor of smoke he wasreceiving.

Prior art methods of componsating for this problem have met with varyingdegrees of success. Regal et al, U.S. Pat. No. 3,503,406 and Thompson,U.S. Pat. No. 3,359,988 use sliding external mechanical sleeves whichmust be positioned so that openings in the slidable sleeve are alignedwith openings in the filter mouthpiece. These methods add to themanufacturing cost in that an additional piece must be added to eachcigarette filter.

Other devices such as those disclosed by Cavelli, U.S. Pat. No.3,858,587 and Sipos, U.S. Pat. No. 3,486,508 employ devices that must beoperated with the smokers teeth as in Cavelli or with the smokers tongueas in Sipos. These methods are not aesthetically pleasing and sufferfrom a lack of uniformity when mass produced at the rate moderncigarettes are manufactured.

It is, therefore, an object of the present invention to provide acigarette wherein the smoke to ventilation air ratio may be changed tosuit the preference of the smoker.

It is also an object of the present invention to provide a cigarettewith variable smoke to ventilation air ratio which is compatible withcurrent high speed cigarette manufacturing equipment.

Yet another object of the present invention is to produce a cigarettewith a variable smoke to ventilation air ratio that is aestheticallypleasing to the smoker.

SUMMARY OF THE INVENTION

According to the present invention, the foregoing and other objects areattained by providing a smoking articles with a first stage filter whichis rigidly attached to the tipping paper at the mouth end of themouthpiece. A second stage filter element located forward of the firststage element is free to slide axially and may be made to move rearwardby tapping the mouthpiece end of the smoking article on a hard surface.Rearward movement of the second stage filter element covers some of theventilation holes located in the tipping paper between the first stageand second stage filter element which increases the smoke to ventilationratio thus increasing the flavor of the cigarette.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendentadvantages thereof will be readily apparent by reference to the followdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a perspective view, partially broken away, of a smokingarticle according to the present invention;

FIG. 2 is a longitudinal cross-section of the invention shown in FIG. 1;

FIG. 3 is a longitudinal cross-section of the invention shown in FIG. 1wherein the second stage element has moved partially to the rear;

FIG. 4 is a longitudinal cross-section of another embodiment of theinvention; and

FIG. 5 is a longitudinal cross-section of a smoking article according tothe present invention with a third stage filter element.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings and specifically to FIG.1 there is illustrated a preferred embodiment of the invention as itwould be used in a smoking article, in this case a cigarette designatedgenerally by the numeral 10. Cigarette 10 has two major parts, smokingcylinder 12 and filter mouthpiece 14.

Filter mouthpiece 14, which is approximately cylindrical in shape,substantially conforms to the cross-sectional size and shape of smokingcylinder 12. Filter mouthpiece 14 consists of a first stage filterelement 18 and a second stage filter element 19 enclosed by tippingpaper 22. First stage filter element 18 may be of any filteringmaterial, but in the preferred embodiment is cellulose acetate. Plugwrap 20 encloses first stage filter element 18 and is rigidly attachedto tipping paper 22. Second stage filter element 19 is similar inconstruction to the first stage filter element 18, but is not attachedto tipping paper 22 and is thus free to move in an axial direction.Filter elements 18 and 19 may be used without plug wrap 20. For example,a nonwrapped acetate filter element, in which the outer surface has beenbonded together with heat may be used.

Tipping paper 22 is air impervious and attaches filter mouthpiece 14 tosmoking cylinder 12. Ventilation holes 16 in air impervious tippingpaper 22 admit outside air to filter mouthpiece 14 in the space betweenfirst stage filter element 18 and second stage filter element 19.

As smoking article 10 is consumed, smoke from the burning coal of thecigarette travels through smoking cylinder 12. Air also enters smokingarticle 10 through ventilation holes 16 and mixes with the smoke infilter mouthpiece 14. In modern, highly diluted, highly filteredcigarettes the flavor of the resulting smoking article may be such thatsome smokers are not satisfied. In this event, the mouthpiece 14 ofsmoking article 10 may be tapped on a hard surface. This causes secondstage filter element 19 to slide toward first stage filter element 18,as shown in FIG. 3, occluding some of ventilation holes 16. Sinceventilation air must now be drawn through ventilation holes 16, porousplug wrap 20, and second stage filter element 19, less ventilation airenters filter mouthpiece 14. Thus, the resulting smoke to ventilationair ratio will be higher than in the cigarette before movement of secondstage filter element 19 to the rear, resulting in a more highly flavoredcigarette.

FIG. 4 shows another embodiment of the invention in which filterelements 18 and second stage filter element 19 have not been enclosed bya plug wrap. Also in this embodiment, ventilation holes 16 are locatedat the forward end of filter mouthpiece 14. Thus, ventilation air musttravel through second stage filter element 19 resulting in a strongerflavored cigarette. In this embodiment, tapping filter mouthpiece 14against a hard surface moves second stage filter element 19 towardsfirst stage filter element 18 uncovering ventilation holes 16, thus,decreasing the smoke to ventilation air ratio. Therefore, thisembodiment produces a weaker flavored cigarette when the filtermouthpiece 14 is tapped against a hard surface. This embodiment might beuseful for changing the ventilation ratio after the cigarette has beenpartially smoked when the flavor normally becomes stronger as the lengthof the smoking cylinder 12 decreases.

FIG. 5 shows another embodiment of the invention with a third stagefilter element 21. All three filter elements in this embodiment areshown with a non-wrapped acetate filter although here also a wrapped ornon-wrapped filter element could be used. First stage filter element andthird stage filter element are rigidly attached to tipping paper 22.Second stage filter element 19 is free to move axially in filtermouthpiece 14. This embodiment prevents shifting of the tobacco whenfilter mouthpiece 14 is tapped since third stage element 21 is rigidlyattached directly behind smoking cylinder 12.

The embodiment shown in FIG. 5 may also be used as a detachablecigarette holder. In this case, tipping paper 22 would be more rigidthan the earlier embodiments, plastic would be a suitable material, andwould not be attached to smoking cylinder 12. When used as a cigaretteholder the smoking cylinder would be inserted into mouthpiece 14. Smoketo ventilation air ratio would be adjusted as described below.

It is thus seen that in a cigarette according to the present invention,the smoke to ventilation air ratio may be varied by the smoker simplyand effectively. It is also seen that a cigarette according to thepresent invention is of simple construction and compatible with modernhigh speed cigarette making machines.

I claim:
 1. In a smoking article the improvements which comprise:afilter mouthpiece attached to one end of said smoking article by airimpervious tipping paper.[.;.]. .Iadd.having .Iaddend. a second stagefilter means mounted in said mouthpiece behind the tobacco portion ofsaid smoking article and free to move in an axial direction in saidmouthpiece in response to tapping said mouthpiece on a hard surface; afirst stage filter means rigidly mounted in said mouthpiece behind saidsecond stage filter means such that there is space for axial movement ofsaid second stage filter; and ventilation holes in said air impervioustipping paper forward of said first stage filter and behind the tobaccoportion of said smoking article.
 2. A smoking article as in claim 1wherein a third stage filter means is rigidly mounted in said mouthpieceforward of said second stage filter means and behind the tobacco portionof said smoking article.
 3. A smoking article as in claim 1 wherein saidventilation holes are located immediately behind the tobacco portion ofsaid smoking article.
 4. A smoking article as in claim 1 or 2 whereinsaid filter means are enclosed in a porous plug wrap.
 5. A smokingarticle as in claim 1 or 2 wherein said filter means are non-wrappedacetate filters.
 6. A filter mouthpiece comprising:an air imperviousouter shell; a third stage filter means rigidly mounted near one end ofsaid outer shell; a first stage filter means rigidly mounted near theopposite end of said outer shell; a second stage filter means mounted insaid mouthpiece between said first and third stage filter means and freeto move axially in said mouthpiece in response to tapping saidmouthpiece on a hard surface; and ventilation holes in said airimpervious outer shell between said first stage and third stage filtermeans.
 7. A smoking article as in claim 1 or 2 .[.or 6.]. wherein saidventilation holes are located immediately forward of said first stagefilter means.
 8. A smoking article as in claim 2 .[.or 6.]. wherein saidventilation holes are located immediately behind said third stage filtermeans. .Iadd.
 9. A filter mouthpiece as in claim 6 wherein saidventilation holes are located immediately forward of said first stagefilter means. .Iaddend. .Iadd.10. A filter mouthpiece as in claim 6wherein said ventilation holes are located immediately behind said thirdstage filter means. .Iaddend. .Iadd.11. A filter mouthpiece as in claim6 wherein said filter means are enclosed in a porous plug wrap..Iaddend. .Iadd.12. A filter mouthpiece as in claim 6 wherein saidfilter means are non-wrapped acetate filters. .Iaddend. .Iadd.13. Afilter mouthpiece for a smoking article, said mouthpiece having aforward end to be disposed to receive smoke drawn into the mouthpiece,and a rearward end to be received in the mouth, consisting essentiallyof:tipping paper formed into a cylinder and adapted to be attached to asmoking cylinder at its forward end and to define the exterior wall ofsaid mouthpiece; a first cylindrical filter element that is disposed inthe cylinder formed by said tipping paper at the rearward end of saidmouthpiece and that is rigidly secured to the inner surface of thetipping paper, a second cylindrical filter element that is disposed inthe cylinder formed by said tipping paper at its forward end, in spacedrelation to at least one of said forward end of the mouthpiece and saidfirst filter element, to define a cylindrical chamber within saidmouthpiece that is bounded by and extends to the inner surface of saidtipping paper, said second filter element is free to move in an axialdirection within said cylindrical tipping paper, in response to tappingsaid mouthpiece on a hard surface, and said tipping paper having atleast one aperture that can communicate with said chamber to admit airto said chamber. .Iaddend. .Iadd.14. The filter mouthpiece of claim 13wherein both of said filter elements are enclosed respectively in acylindrical porous plug wrap, wherein the plug wrap about said firstfilter element is rigidly secured to the inner surface of said tippingpaper. .Iaddend. .Iadd.15. The mouthpiece of claim 13 wherein saidsecond filter element is spaced from said first filter element, todefine said chamber between said two filter elements. .Iaddend..Iadd.16. The filter mouthpiece of claim 13 wherein said second filterelement is free to move in an axial direction within said cylindricaltipping paper, in response to tapping the rearward end of saidmouthpiece on a hard surface, and wherein after causing such movement tooccur, said second filter element has been moved toward said firstfilter element and is spaced from a said smoking cylinder and from theforward end of said mouthpiece. .Iaddend. .Iadd.17. The filtermouthpiece of claim 16 wherein said second filter element is free tomove in an axial direction within said cylindrical tipping paper, inresponse to tapping the forward end of either of said mouthpiece or ofan attached smoking cylinder, on a hard surface. .Iaddend. .Iadd.18. Thefilter mouthpiece of claim 13 comprising a third cylindrical filterelement that is rigidly secured in place inside said cylindrical tippingpaper, at the forward end of said mouthpiece, for abutment against thesmoking material in an attached smoking cylinder. .Iaddend. .Iadd.19. Afilter cigarette comprising a smoking cylinder and, attached to one endof said smoking cylinder, a filter mouthpiece according to claim 13..Iaddend.